Frequently, a storage system includes one or more storage devices for storing data on magnetic or optical storage media. For example, a magnetic storage system can be a direct access storage device (DASD) or a hard disk drive (HDD) and include one or more platters and a disk controller to manage operations on the platters. The platters are frequently made of aluminum alloy or a mixture of glass and ceramic with a magnetic coating. The platters can be stacked vertically on a spindle by placing the spindle in the center of the platters. The spindle can be turned by a motor at velocities ranging from three to fifteen thousand revolutions per minute.
Typically an HDD uses an actuator assembly for positioning read/write heads at the desired location of a platter to read data from and/or write data to a platter. The read/write heads can be mounted on what is known as a slider. Generally, a slider provides mechanical support for a read/write head and electrical connections between the head and the drive.
During drive operation the surface of a platter can be damaged possibly resulting in a loss of data. One possible source of damage to the platter can result from a read/write head coming into contact with the surface of the platter. The rotation of a platter around the spindle causes air to move beneath a slider. The slider can glide over the moving air at a uniform distance above the surface of the rotating platter, thus, avoiding contact between the read/write head and the surface of the platter.
The slider includes a pattern of protrusions (air bearing design) on the air bearing surface (ABS) of the slider, which enables the slider to “fly” at a desired height above a platter. A slider can be coupled to a suspension to form a head gimbal assembly (HGA). The HGA can be coupled to an actuator arm, which is a part of an actuator assembly, to move and support the HGA.
FIG. 1 depicts a prior art storage system for reading data from and/or writing data to a storage medium that requires a dedicated landing zone at the outer diameter. For example, as depicted in FIG. 1, the storage system 100 includes a platter 125, a slider 110, a suspension 115, and a ramp 105. The platter 125 has a center 120, an outer diameter 130, an inner diameter 140, and a dedicated landing zone 135. The platter 125 can be mounted on a spindle at its center 120. The slider 110 is coupled to the suspension 115 and has an air bearing surface 112 (ABS) for reading data from and writing data to the platter 125. The slider 110 is depicted at an operating fly height 145.
When a storage system 100, such as a disk drive, is off, the platter 125 associated with the storage system 100 is not rotating and the slider is “parked,” for example, on a ramp 105. When a read or write operation is initiated, the platter 125 begins to rotate. The slider 110 exits 107 its parked position on the ramp 105 and is positioned at a height 145 above the platter 125 at which the read/write head can read data from or write data to the platter 125. This height 145 shall be referred to as the operational fly height 145. The process of positioning the slider 110 at the operating fly height 145 is frequently referred to as “loading” the slider 110 or simple as a “load process.” When an operation, such as reading or writing data, has been completed, the slider 110 can be parked, for example, on the ramp 105. The process of parking the slider 110 on the ramp 105 is commonly referred to as “unloading” the slider 110 or simple as an “unload process.”
Unloading and loading the slider 110 are critical operations as there is a danger that the read/write heads may come into contact with the platter 125 resulting in damage to the platter 125's surface. To prevent damage, a dedicated landing zone 135 is associated with the outer diameter 130 of the platter 125 where no data is written to. Thus, no data will be lost in the event that the read/write head comes into contact with the surface of the platter 125. However, using a dedicated landing zone 135 at the OD 130 results in a reduction of approximately 7% of the amount of data that could have been stored on the platter 125.
For these and other reasons, a method for loading a slider that eliminates the need for a dedicated landing zone at the outer diameter of a platter would be valuable.